The engine of a typical automotive vehicle is controlled by an electronic controller that may control ignition, air/fuel mixture, and the like. Input signals to the controller are received from sensors such as temperature sensors, accellerometers, etc. that are mounted externally of the controller. These sensors are usually mounted either on the engine or in close proximity to the device or component whose operation is to be measured.
Likewise, a conventional automotive transmission is controlled by an enclosed electronic controller that receives inputs from external sensors, such as clutch pressure switches.
The foregoing arrangements are not entirely satisfactory in that an undesirably large amount of wiring is required to couple electrical signals from the sensors to their associated control units. Further, such arrangements tend to require too many connectors and too may sensors, thus leading to a potentially less reliable system.